Process of treating petroleum oils



Mutti,

F. G. GRAVES Anl Filed March 2. 1927 July 19, 1932.

l PRocEss oF TREATING PETROLEUM oILs Nw T E@ @Ws HNA Patented July 19,' 1932 1,867,697

UNITED STATES PATENT- OFFICE FRANCIS G...CRAvEs,. or ALAMEDA, CALIFORNIA, ASSICNOR To STANDARD OrL ComrANY OE CALIFORNIA, OE SAN FRANCISCO, CALIFORNIA, A CORPORATION OE DELA- WARE I PROCESS or TREATINC PETROLEUM OILS Application filed March 2, 1927. Serial No. 171,951. i

' I This invention relates to improvements in processes of treating petroleum oils, and refers more particularly to a process of treating petroleum oils to remove gum-forming abodiesto deodorize, decolorize, and desulproducts using ^tain, prior to suitable furize relatively -light petroleum distillates, particularly those distillates which are at this time employed as fuel for internal combustion engines.

It is well known'that distillates used for motor fuels and illuminating purposes contreatmen't, undesirable products which would render the distillate unfit for use'if not removed. It has ,been heretofore common practice to remove the undesirable products such as sulfur compounds, resins, gums, water, or other objectionable lowed by redistillation. Resort has also been had to the use of metals Or metallic salts to remove from certain oils -which are particularly difficult to refine sulfur and sulfur com-` pounds.

In addition to those impurities which can be removed by the usual acid with caustic treatment or simple application of metals or metallic salts, there are in some distillates, such as those obtained by cracking a typical California crude petroleum oil, certain gumforming bodies which cannot be entirely 'removed by the usual methods. The presence of these gum forming bodies can be readily determined b the well known copper bowl test. v

I have discovered that light distillates may be made to pass a satisfactory copper bowl or gum test if they are rst contacted with metallic copper and then contacted with'an absorbent material, The absorbent material may be of the type commonly known as contact clays, many of which are mined in California, andof which Otay clay and Janney clay are examples, or such minerals as montmorillonite or fullers earth. The action of the copper upon the gum forming bodies of the light distillates is apparently to polymany divers processes. The` customary treatment for the removal of these' .products consists in a serles of appllcations tating merize them so that they can be subsequently removed by the absorbent material,v The treatment of Oils by copper alone or byan absorbent agent alone will not effect theremoval of the gum-forming bodies from certain oils so that the oils will pass a satisfactory gum test; however, I have discovered that the combined treatment with copper and clay eects a substantially complete removal of the gum-forming bodies from these oils.

In the drawing, l have illustratedf one form of apparatus `that may be employed for carrying out the process embodying this invention, and wherein 1 indicates a source of. feed which maybe any suitable ypetroleum oil distillate. .The petroleum distillate is pumped by a feed pump 2 through a preheater 3 to one ,or more'treaters 4 and 5. Valves 6 and'? areprovided in the inlet and outlet lines 8 and 9, respectively, vof the treaters may be raised by raising the tem- .I

by `tests made by treating samples with clay. The distillate is then passed through the con duit 11 into a mixing tank 12 and mixed with contact clay from a storage tank-'13, fed into the mixer 12by means of a conveyor 14. Any suitable or desirable means may be employed for agitating or thoroughly comminglingthe clay and distillate in the mixing tank 12.

After the distillate has been thoroughly contacted with the clay in the mixing tank 12, the same is'passed by means of a pump 15 into a still 16.4 Any suitable form of agimeans, such as illustrated at 17, may be employed for agita-ting the mixture Within the still 16 and the means 17 are herein illustrated as comprising a screw agitator or scraper 18 driven by a'pulley 19 from any suitable or desirable source of power.

70 i treaters 4 and 5 so that the pressure in-these Yclay and bottoms.

l been yfound to Heatis applied to the still by external firing means or by any other means, as desired.

A fractionating tower 20'of any suitable or desirable form is provided on the still 16 from which the desired vapors pass through a condenser 21 into a storage tank 22. The draw-oft' line 23 is provided at the bottom of the still 16 for the removal of the In many cases it is believed advisable to treat the distillate after the same has been distilled olf the contact clay with caustic (sodium hydroxide, potassium hydroxide, etc.). This may be done by introducing the caustic into the vapor line that leads from the still 16 to the or preferred manner as is well understood in the art.

While the apparatus hereinbefore set forth is exceedingly well adapted for carrying out the process embodying this invention, it is to be understood that the process embodying this invention may be accomplished by either batch or continuous operation. The use of heat and super-atmospheric pressure during the copper treating step of this process has be extremely advantageous. In carrying out the process embodying batch treat-ment can be carried out either by refluxing the distillate over copper or in a closed system under pressure.

The time of treatment of the distillate with the copper has been found to vary, depending upon the amount of lcopper used and it has also been found that the action of the copper on the distillate to remove or polymerize the gum-forming bodies is increased by increasing the temperature of the distillate during the treatment.

Thecontinuous process is preferably carried out-entirely-in a closed system.

`During the treatment ofthe distillate with copper, it has been found that the-copper becomes coated with suliide and oxide which may be rendered lit for further use by washing from time to time with dilute sulfuric acid.

Theclay treatment which follows the copper treatment may be carried out in several different ways, as follows:

l. The contact clay may be introduced directly into the still together with the oil which has been previously copper treated, and the desired boiling point stock distilled off by direct fire distillation or other application of heat. Y Y

2. The distillate maybe contact treated with the contact clay applied to the distillate in the liquid phase as, for example, in the mixer tank 12.

3. The distillatein the vapor phase Vmay be contacted .with the contact clay in any suitable or desirable manner.

4. It is also'unde'rstood that substantially condenser 2l in any desired or in the vapor phase.

a iinal product having the boiling point y range desired.

It will beobvious from the foregoing'that by the present process, the gum-forming bodies present in a distillate are polymerized and subsequently removed so that the iinal products will give no gumming in the copper bowl test. In accordance with this process, there is also produced a gasoline or motor fuel which is non-corrosive, and a water- White, stable colored product which is lower in sulfur content than the original product and which will give an improved doctor test.

Having fully described the present invention, it is to be understood that the same is of the scope of the appended claims.

I cla-im:

l. A process of treating petroleum distil- ;lates containing gum-forming bodies, comrprising the steps of contacting a distillate '1 containing gum-forming bodies at a temperavthis invention by 'the batch operation, the

ture above atmospheric with metallic copper in the absence of appreciable amounts of copper oxide, separating'the treated distillate from the copper, and then contacting the treated dist-illate, at a temperature above atmospheric, with an adsorbent clay.

2.,A process of treating petroleum distillates,consisting of heating a distillate contained gum-forming bodies, contacting the heated distillate with metallic copper in the absence of appreciable amounts of copper oxide to polymerize such gum-forming bodies, separating the treated distillate from the metallic copper, then mixing'the treated distillate with an adsorbent clay, and finally distilling the distillate `from the mixture.

In a process of treating petroleum distillates containing" gum-forming bodies, the steps of heating a distillate containing gumforming bodies, contacting the heated distillate under pressure with metallic copper in the absence of appreciable amounts of copper oxide to polymerize such gum-forming bodies, separating the treated distillate from the metallic copper, and then contacting the vtreated distillate at superatmospheric tempertillate with clay, and finally distilling the treated distillate from the clay.

5. A process of treating petroleum distil-l lates vcontaining gum-forming bodies, consisting of heating a distillate containing gum-forming bodies, contacting the heated distillate under pressure with metallic copper in the absence of appreciable amounts of copper oxide to polymerize such gum-forming bodies, separating the treated distillate from the metallic copper, then mixing the treated distillate with an adsorbent clay, and inallygdistilling the treated distillate from the mixture. Signed at Richmond, California, this 16th day of February, 1927.

FRANCIS G. GRAVES. 

